Thermoplastic valve



July 22, 1958 R. R. DAHL THEliMOPLASTIC VALVE Filed Dec. 31, 1954JZZZEIZ Ur g the valve seat and wall of the port.

THERMOPLASTIC VALVE Robert R. Dahl, Chicago, 111., assignor to The DoleValve Company, Chicago, Ill., a corporation of Illinois ApplicationDecember 31, 1954, Serial No. 479,046 7 Claims. Cl. 251-48) Thisinvention relates to improvements in valves and more particularlyrelates to an improved form of pressure operated diaphragm valve inwhich the valve body is made from a thermoplastic material, and to animproved method of making the body for the valve.

Heretofore, pressure operated valves having a diaphragm coming intoengagement with a seat surrounding a port in the valve body, to blockthe flow of fluid through the port have been made with moldedthermoplastic valve bodies, one commonly used material being a nylonthermoplastic material. Such valves, while generally satisfactory, havehad an objectionable and harmful water hammer which has been difficultto cure due to distortion of the nylon under the presence of water and/or heat.

Attempts have been made to reduce this water harnmer by providing aresistance to the movement of the diaphragm in a valve closingdirection. One way of reducing this water hammer has been by molding aninsert in the diaphragm to extend from the face of the diaphragm and byplacing a metal grommet on the extending portion of the insert so as toprovide a relatively close fit between the insert and the wall of theport and thus provide a throttling action during valve closing movement.

While this has minimized water hammer, it has not eliminated it, due todistortion of the nylon and the resultant variations in clearancebetween the grommet and port wall.

Another attempt to remedy this difficulty has been by providing a metalinsert in the valve body which defines Such inserts have not beenpractical due to leakage between the metal insert and the nylon body.

I have discovered, as a result of the foregoing efforts to reduce waterhammer of the valve that where the diaphragm seats against athermoplastic seat, and the wall of the port into which the valve fitsis metal, that a sufliciently close fit may be provided between thevalve and the metallic wall of the port to effect a slow closing of thevalve and entirely eliminate harmful water hammer and leakage betweenthe valve body and the insert. 1

It is, therefore, an object of my present invention to remedy theforegoing difficulties by providing a thermoplastic-bodied,pressure-operated valve having an annular seat and a port leadingtherefrom, in which the valve seats against a thermoplastic seat and thewall of the port opening leading from the seat is made from metal.

Another object of my invention is to provide a pressure operateddiaphragm valve having a thermoplastic valve body in which a metalinsert is molded in the diaphragm valve and extends therefrom and has agrommet carried thereby, providing a close fit between the grommet and awall of the port closed by the valve, so as to provide a slow closingvalve and eliminate harmful water hammer effects.

A still further object of my invention is to provide a slow closingpressure operated diaphragm valve in which the harmful effects of waterhammer are eliminated in a simple.v and expeditious manner.

Still another object of my invention is to provide a valve body of athermoplastic material in which the valve seat is formed integrally withthe body of the valve and in which the wall of the port leading from theseat is formed from a metal insert molded within the body of the valve.

These and other objects of my invention will appear from time to time asthe following specification proceeds and with reference to theaccompanying drawing wherein:

Figure 1 is a longitudinal sectional view taken through a solenoidcontrolled pressure operated diaphragm valve constructed in accordancewith my invention, with the solenoid coils for controlling operation ofthe valve broken away;

Figure 2 is a view in side elevation of the bushing, for positioning inthe port wall of the valve,

Figure 3 is a fragmentary view showing the metallic bushing in positionin the port wall at the completion of the molding operation; and

Figure 4 is a fragmentary sectional view showing the port and bushingafter the machining operation thereof.

In the embodiment of my invention illustrated in the drawing, I haveshown a section through a mixing valve of a type somewhat similar tothat shown in the James K. Lund application Serial No. 229,983, filedJune 5, 1951, and entitled Fluid Mixing Valve, issued July 5, 1955,Patent No. 2,712,324. The valve, therefore, need only be shown herein insufficient detail to fully disclose the novel features of my presentinvention.

The valve is shown as having a valve body 10 which may be cast or moldedfrom one of the well known thermoplastic materials, and is then drilledand machined as required. One such thermoplastic material which has beenfound to withstand the high water temperatures encountered in valvesused for washing and dishwashing machines and other domestic appliancesisa nylon thermoplastic material. Other suitable materials are arcylicthermoplastic materials.

The valve body 10 is shown as having an inlet 11 for water at onetemperature. It is also provided with an inlet (not shown) for water ata different temperature. The inlets lead to opposite sides of the valvebody, one inlet 11 leading to an annular passageway 12 within the innermargins of a diaphragm 14 and opening to the outside of the valve body.The other inlet (not shown) leads to a similar annular passageway 15opening to the opposite side of the valve and enclosed by the innermargins of a diaphragm 16 on the opposite side of the valve body 10.

The annular passageways 12 and 15 are enclosed by the respectivediaphragm valves 14 and 16, respectively, and have communication withport openings 17 and 18 leading to a central passageway or mixingchamber 19. The mixing chamber 19 extends along the valve body and opensfrom the opposite end of the valve body from the hot and cold waterinlets, and is shown as having a fitting 20 coupled thereto by acoupling member 21 and sealed to the end of the outlet passageway as bya seal 22.

The outlet fitting 20 forms the outlet for the valve and is shown ashaving a resilient flow control annulus 23 seated at its inlet end. Theflow control annulus 23 is a Well known form and has a central orifice24 leading therethrough of a smaller diameter than the diameter of thepassageway leading through the fitting 19, to effect a restriction inthe cross-sectional area of the orifice 24 upon predetermined increasesin pressure so as to provide a substantially uniform flow through theoutlet from the valve for varying pressure conditions.

The diaphragm valves 14 and 16 are each of a similar construction so oneonly need herein be, shown or described in detail. The diaphragm valve14 is preferably formed from rubber and elastomer or other likeresilient material and has a flange 25 extending along its outer edgeand fitting within an annular groove 2d formed within the valve body 16.The diaphragm valve also has a thickened central portion, an inner face27 of which is engageable with an annular seat 29 extending.

around the port opening 17 to block the flow of fluid through said portopening.

The thickened central portion of the diaphragm valve 14 is shown ashaving a flanged metal insert 3G molded therein for reinforcing thesame. The insert 36 may be a stamped insert and the flange thereof isshown as being apertured for locking of the rubber of the diaphragm tothe insert and as having a tubular portion projecting from the face 27of the valve and forming a passageway member registering with a centralpassageway 31 leading through the diaphragm valve. The tubularprojecting portion of the reinforcing insert 30 is shown as having ametal grommet 32 fitting thereon and extending within a metallic bushing33 molded within the valve body, as will hereinafter more clearly appearas this specification proceeds. The grommet 32 and bushing 33 may bemade from brass or any other suitable noncorroding metal.

It may be seen from Figure 1 that the grommet 32 has a relatively closefit with the metallic bushing 33 when the valve is moving to a closedposition so as to provide a throttling action on the flow of waterduring valve closing movement by pressure on the outside of thediaphragm of the valve.

The diaphragm valve 14 is also provided with a bleeder passageway .4outwardly of the thickened portion thereof and leading into a diaphragmchamber 35 formed between the outer side of the diaphragm valve 14 andthe inside of an end closure cap 36, having a central integrally formedguide 37 extending therefrom and having an armature 39 guided therein.It is, of course, understood that more than one bleeder passageway maybe provided and that the number and size of bleeder passageways governsthe speed of valve closing movement and reduces the chances of valvefailure due to dirt in the bleed hole.

The end closure cap 36 is shown as abutting the outer peripheral portionof the diaphragm valve 14 and as being retained thereto as by a yoke 44?and machine screws 41 extending through said yoke, and threaded within ayoke 43 engaging an opposite end cap 36 and retaining the diaphragmvalve 16 to the opposite side of the valve body 10 from the diaphragmvalve 14.

The armature 39 has an integrally. formed conical valve 44 at its lowerend, engageable with the passageway 31, leading through the centralthickened portion of the valve 14, by a spring 45 seated at one endagainst the outer end of the armature 39 and at its opposite end in anend wall of the guide passageway 37 of the end cap 36.

The armature 39 forms the armature of a solenoid 46, the coil of whichencircles the guide member 37 and is not herein shown or described indetail since it forms no part of my present invention, and is clearlyshown in the aforementioned James K. Lund application Serial Uponenergization of the solenoid 46, the valve 44 on the end of the armature39 will move out of engagement with the passageway 31 leading throughthe diaphragm valve. This will relieve pressure within the diaphragmchamber 35. Pressure on the inner or underside of the diaphragm willthus move the valve 14 into an open position out of engagement with theseat 29, to aceom: modate the flow of fluid through the port 17 into thecentral mixing chamber 19.

Upon deenergization of the solenoid 46, the spring. 45 will engage thevalve 44 on the end of the armature 39 with the passage. 31'leadingthrough the thickened pot:

tion of the valve 14. Fluid under pressure flowing through the bleederpassageway 34 into the diaphragm chamber 35 will then effect closing ofthe valve.

, Referring now in particular to the insert or bushing 33 and the mannerin which said bushing is molded within the valve body to form the wallof the port 17, the bushing 33 is shown as having an enlarged diametercentral portion 50, which is knurled to provide a surface to be grippedby the thermoplastic material during the molding operation The bushing33 also has reduced diameter wall portions 51, 51 on opposite sides ofthe knurled enlarged diameter central portion thereof to provideshouldered support surfaces on the bushing, holding the bushing withinthe port opening. The bushing 33 is suitably supported prior to molding,with its outer edge so located that it will be inwardly of the seat 29at the completion of the molding operation, as shown in Figure 3 whichshows the bushing 33 in its position as molded before machining of theseat.

After the molding operation, the valve seat '29 is then machined toprovide a generally rounded outer surface with an intermediate flatseating surface indicated by reference character 53 in Figure 4 andengaged by the face 27 of the valve 14 upon closing of the valve 14, toseal the port opening 17 from the passage of fluid therethrough. Theouter margin of the wall of the port opening is shown as being machinedat an angle, which may be an angle of 30, the nylon valve body beingmachined as well as the entering end of the inner margin of the bushing33.

It may be seen from the foregoing that I have provided a valve and bodyparticularly suited to be molded from a nylon thermoplastic material, inwhich the seat of the valve is plastic and the wall of the port leadingfrom the seat is metal and spaced inwardly from the seat so as to avoidany leakage of fluid between the seat and metal insert when the valve isclosed.

It may further be seen that the metal insert provides a uniform boreinto which the metal grommet 32 fits during valve closing movement,which is not subject to the distortions which the nylon body undergoesin the presence of water and heat.

It may also be seen that this provides a relatively close uniform fitbetween the grommet 32 and bushing 33 so as to provide suflicientresistance to valve closing movement to effect a slow closing valve andeliminate undesirable and harmful water hammer.

It will be understood that modifications and variations of the presentinvention may be eflected without departing from the spirit and scope ofthe novel concepts thereof as defined by the appended claims.

I claim asmy invention:

1. In a fluid pressure operated valve, a thermoplastic valve body havinga chamber, a port leading into said chamber and terminating at theoutside of said valve body in an annular valve seat, an annular metalinsert recessed in the wall of said port in inwardly spaced relationwith respect to said seat and having an inner wall forming a portion ofthe wall of said port, 21 diaphragm sealed to said valve body andengageable with said seat to block the passage of fluid through saidport, and a metallic passageway member extending from said diaphragm forproviding a close surface coacting with the inner wall of said insertupon valve closing movement.

2. In a fluid pressure operated valve, a thermoplastic valve body havinga central chamber, a port leading into said chamber and terminating atthe outside of said valve body in an annular seat, an annular metalinsert recessed in the wall of said port in inwardly spaced relationwith respect to said seat and having an inner wall defining a majorportion of the wall of said port, a diaphragm sealed to said valve bodyat its periphery and extending over said port and-seat and having athickene en portion. ha g a a fa on. he id thereof facing said seat,said diaphragm also having a central passageway leading therethrough andhaving metal insert reinforcing said thickened portion and extendingfrom said flat face into said port when the valve is closed, said inserthaving a passageway leading therethrough in registry with said centralpassageway and having a metal grommet mounted thereon and extending fromsaid flat face for close fitting coaction with the inner wall of saidinsert upon valve closing movement.

3. In a fluid pressure operated valve, a valve body formed of plastichaving an outlet passageway therein, a port communicating with saidpassageway, a diaphragm valve extending over said port and movable underfluid pressure to engage an end of said port and close the same, saiddiaphragm having a projecting portion extending within said port duringvalve closing movement with a relatively close fit therewith, and saidport having a metal insert recessed within said valve body inwardly ofsaid end of said port and having an inner wall forming a uniformdiameter wall portion of said port to form said relatively close fitwith the projecting portion of said diaphragm whereby a throttling offluid will occur between the projecting portion and metal insert duringvalve closing movement to slow the closing and reduce water hammer.

4. In a fluid pressure operated valve, a valve body formed of plasticand having an outlet passageway therein, a port communicating with saidpassageway, a diaphragm valve extending over said port and movable underfluid pressure to engage an end of said port and close same, a tubularprojecting portion on said diaphragm valve extending into said port whenthe diaphragm moves to engagement with the port to close the valve, anda metal insert recessed within said valve body in registry with saidport and having an inner Wall forming a portion of the wall of said portand being spaced inwardly of said end of said port, the inner wall ofsaid insert having a relatively close fit with said tubular projectingportion whereby a throttling of fluid will occur when the tubularprojecting portion moves within the metal insert as the diaphragm valvecloses to slow the valve closing.

5. A plastic valve body having an outlet passageway therein, a portcommunicating with said passageway and terminating at one end in anannular valve seat, valve means for closing said port having an attachedtubular portion projecting into said port when moving to closedposition, and a metal insert recessed within the wall of said port andhaving an inner wall forming a continuation of the wall of said port ininwardly spaced relation with respect to said seat to provide aleakproof thermoplastic seat and uniform diameter port leading from saidseat, said insert having a relatively close fit with said tubularportion of the valve means to provide a throttling effect on fluidflowing through the port to slow the closing of the valve.

6. In a fluid pressure operated valve, a valve body formed of plasticand having an outlet passageway therein, a port communicating with saidpassageway and terminating at its outer end in an annular valve seatfacing the outside of said valve body, the greater portion of the wallof said port comprising an annular metallic insert recessed within saidvalve body in inwardly spaced relation with respect to said seat andhaving an inner wall flush with the wall of said port, said inserthaving a shouldered outer wall for retaining said insert in said valvebody, and a valve member movable to closed position'to terminate flowthrough said port and having a portion projecting into said port with arelatively close fit within said metallic insert to throttle fluidflowing through the port when moving to closed position whereby theclosing of the valve is slowed to prevent water hammer.

7. In a fluid pressure operated valve, a valve body formed of plasticand having an outlet passageway therein, a port communicating with saidoutlet passageway and terminating at its outer end in an annular valveseat facing the outside of said valve body, the greater portion of thewall of said port comprising an annular metallic insert recessed withinsaid body inwardly of said seat and having an inner wall flush with thewall of said port and an outer wall shouldered at opposite ends thereoffor restraining said insert from movement with respect to said valvebody, and a valve member movable to closed position to terminate flowthrough said port and having a portion projecting into said port with arelatively close fit within said metallic insert to throttle fluidflowing through the port when moving to closed position whereby theclosing of the valve is slowed to prevent water hammer.

References Cited in the file of this patent UNITED STATES PATENTS316,588 Weber Apr. 28, 1885 1,999,599 Smith Apr. 30, 1935 2,025,368Wissler Dec. 24, 1935 2,589,682 Dudis Mar. 18, 1952 2,675,204 JohnsonApr. 13, 1954 2,712,324 Lund July 5, 1955

